In wound healing and surgery, blood clotting must be controlled for patient safety. Blood clotting is triggered by an enzymatic cascade that ultimately activates the protein thrombin, which cleaves fibrinogen to form a clot. Manipulation of blood clotting is achieved predominantly by administering anticoagulants such as heparin, warfarin (coumarin), and others which inhibit blood clotting. However, these anticoagulants suffer many limitations, causing them to rank as the leading cause of death in adverse drug reactions in therapeutic use in the US. These anticoagulants can only inhibit coagulation, so their ability to control clotting is inherently one-sided. Furthermore, heparin, the most prevalently used anticoagulant, is a polydisperse polymer that acts nonspecifically, inhibiting not one but several species in the clotting cascade. Heparin is obtained from livestock (pig) intestines, where risk of contamination is significant and can be fatal. More importantly, these anticoagulants have no specific antidote, and reversing their effect is predominantly achieved by clearance, which can vary greatly among people. Current recommendations include use of activated charcoal to non-specifically absorb the drug.